As of Encode-1.64, 'euc-jp' does support euc-jisx0213 for decoding. However, 'euc-jp' in Encode and 'euc-jisx0213' differ as follows;

euc-jp euc-jisx0213
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Decodes.... (0201-K|0208|0212|0213) ditto
Round-Trip (|0) (020-K|0208|0212) JIS X (0201-K|0213)
Decode Only (|3) those only found in 0213
those only found in 0212
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